Re 2: do you know of tools that don't involve the cloud and allow you to do such analysis? Ideally FLOSS. I could only find DbSNP and SNPedia but they are datasets, not sure if there are tools built on top of that like Promethease.
Re WGS there are a lot of well established tool chains that are FLOSS (eg https://github.com/bcbio/bcbio-nextgen). You could run alignment and variant calling on a beefy workstation. A laptop would potentially work. Easy to test this with publicly available raw data. Another option: The sequencing provider often will run alignment and some default variant calling for you. Annotating and analysing these variants can be done on pretty much any computer, all with open source software. A SNP chip is even easier to deal with as the computational requirements are less.
Interpreting the results is a more manual process. Really depends on what you are interested in.
